GB1579322A - Gas burners - Google Patents

Description

(54) IMPROVEMENTS IN GAS BURNERS (71) We GLYNWED DOMESTIC AND HEATING APPLIANCES LIMITED, a British Company of Oxford Street, Bilston, Staffordshire, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to gas burners for domestic appliances of the kind in which a gas/air mixture is supplied to jets or flame ports in a burner body through one or more intake tubes and, in use, gas is injected into the intake tube from an injector simultaneously with air being entrained into the gas stream.

In known gas burners of the kind set forth the intake tube is of substantial length and is separate from or projects from the body by a substantial length. Thus considerable space is required to accommodate both the tube and the body and, particularly when the tube is radially arranged with respect to the body, there is a tendency for the gas/air mixture to have a swirling motion being provided with a circumferential component of movement which may cause flame instability.

The present invention consists in a gas burner of the kind set forth for domestic appliances in which the intake tube is housed substantially within the body, and a flow path is defined in the body by way of which the gas/air mixture leaving the inner end of the tube is directed back towards the outer end of the tube and then towards the inner end again before issuing from jets or flame ports of the burner.

This has the advantage that the overall dimensions of the burner can be reduced substantially to enable the burner to be installed within a smaller space and the gas/air mixture which issues from the jets or flame ports has substantially only a radial component of movement or an upwardly directed radial component so that flame stability is improved.

For compactness, preferably the tube is housed wholly within the body of the burner.

In a preferred form, a burner chamber is defined within the body between opposed first and second end walls and a continuous side wall and the tube projects through the first end wall to a position spaced by a relatively short distance from the second end wall, a passage forming part of the flow path being defined by a space between the tube and the second end wall and between the tube and the side wall. Thus, the direction of movement of the gas/air mixture leaving the inner end of the tube is reversed by impingement on the inner end of the first end wall. The direction of movement is reversed a second time before the mixture issues from the jets or flame ports.

The free outer end of the intake tube may have an entry of the venturi-type, and the body may be provided with location means for locating the burner with respect to the injector, which may be of the single or multi-hole type and having a conventional pipe connection to a supply of gas.

Some burners in accordance with our invention are illustrated in the accompanying drawings in which: Figure 1 is a longitudinal section through a boiling burner of a gas cooker; and Figure 2 shows longitudinal sections through halves of two modified burners.

The burner 1 illustrated in Figure 1 of the drawings is mounted in the frame 2 of a gas cooker above an injector 3 which is supplied with gas from a supply connection 4 through a regulator 5. The burner 1 comprises a body formed from complementary upper and lower parts 6 and 7 together constituting upper and lower end walls and a continuous side wall in which are provided spaced jets of flame ports 8 disposed above flame retention ports 9. The upper part 6 is of cup-shaped outline with the depending rim which is of substantial radial thickness being received within the upstanding rim of the lower part 7 which is also of cupshaped outline. The lower part 7 incorporates an upstanding integral intake tube 10 which terminates short of the upper end wall.The lower end of the intake tube 10 is a venturi outline at 11 to facilitate the entrainment of air in a gas stream injected into the tube 10 by the injector 3, and an annular space 12 within the chamber of the body and of the same length as the portion of the tube within the body provides connection between the tube 10 and both series of ports 8 and 9.

The ports 8 and 9 of each series comprise slots in the skirt of the upper part 6 with lands between adjacent slots seating against the continuous rim of the lower part 7. Each slot has an upwardly extending axial portion 13 leading at its upper end into a radial portion 14 which is inclined slightly upwardly with respect to a transverse plane. Thus before issuing from each port in a generally radial direction the direction of flow of the gas/air mixture is reversed twice.

In the burners illustrated in Figure 2 the right hand portion is similar to the burner of Figure 1 except that a third annular side wall portion 15 is disposed between the upper and lower parts 6 and 7 with the slots 14 of the ports 8 and the slots 13 and 14 of the ports 9 being constituted in the wall portion 15. Also the tube 10 is received in a counterbore recess 16 in the end wall of the lower part 7 which continues the tube to the inlet 11 of venturi outline.

In the burners described above the upper and lower parts 6 and 7 are both formed from castings.

In the burner illustrated in the left hand portion of Figure 2 the upper part 6 which also contains the flame ports 8 is of fabricated metal construction and the lower part 7 comprises a casing of cup-shaped outline through the closed end wall of which projects the intake tube 10 which is of tubular metal construction.

The lower end of the tube is of frusto conical outline at 17 to define the venturi type inlet.

In a modification the lower part may also be of pressed metal or other fabricated metal construction with a slotted annular port ring disposed between the side walls or skirts of the upper and lower parts.

In a further modification flame retention means to stabilise the flames at the main flame ports may be provided by suitably altering the size and shape of the burner's outer flange or rim adjacent to the flame ports.

The burners may also be constructed from ceramic material or glass. Due to the electricity insulative nature of the material this is of particular advantage when it is desired to incorporate an electrical igniter in the burner since no other insulator has to be provided.

Our invention can be applied to other burners, for example to burners for gas cooker ovens, space heating appliances and gas-fired water heaters, and it is envisaged that all the burners will be suitable for use with natural and town gas, and liquid petroleum gases. Of course, such further burners will be of linear outline and may employ more than one intake tube projecting into the burner chamber.

WHAT WE CLAIM IS: 1. A gas burner of the kind set forth for domestic appliances in which the intake tube is housed substantially within the body, and a flow path is defined in the body by way of which the gas/air mixture leaving the inner end of the tube is directed back towards the outer end of the tube and then towards the inner end again before issuing from jets or flame ports of the burner.

2. A gas burner according to Claim 1, in which the tube is housed wholly within the body of the burner.

3. A gas burner according to Claim 1 or 2, in which a burner chamber is defined within the body between opposed first and second end walls and a continuous side wall, and the tube projects through the first end wall to a position spaced by a relatively short distance from the second end wall, a passage forming part of the flow path whereby the gas/air mixture is directed away from the inner end of the tube and towards the outer end of the tube being defined by a space between the tube and the second end wall and between the tube and the side wall.

4. A gas burner according to Claim 3, in which the jets or flame ports are positioned in the side wall and each port comprises a first substantially axial portion extending from the passage towards the second end wall and directing the mixture towards the inner end of the tube, and a second substantially radial portion extending out of the body at the upper end of the first portion.

5. A gas burner according to Claim 4, in which the ports comprise an upper series of flame ports and a lower series of flame retention ports.

6. A gas burner according to any preceding claim in which the free outermost end of the intake tube has a venturi-type entry.

7. A gas burner according to any preceding claim in which the body is provided with location means for locating the burner with respect to the injector, which has a pipe connection to a supply of gas.

8. A gas burner according to Claim 7 as dependent from any of Claims 3 to 5, in which the tube is received in a counterbore recess in the first end wall, the recess continuing the tube to an inlet of venturi outline.

9. A gas burner substantially as herein described with reference to and as illustrated in Figure 1 of the accompanying drawings.

10. A gas burner substantially as herein described with reference to and as illustrated on the right hand portion of Figure 2 of the accompanying drawings.

11. A gas burner substantially as herein described with reference to and as illustrated on the left hand portion of Figure 2 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. series of ports 8 and 9. The ports 8 and 9 of each series comprise slots in the skirt of the upper part 6 with lands between adjacent slots seating against the continuous rim of the lower part 7. Each slot has an upwardly extending axial portion 13 leading at its upper end into a radial portion 14 which is inclined slightly upwardly with respect to a transverse plane. Thus before issuing from each port in a generally radial direction the direction of flow of the gas/air mixture is reversed twice. In the burners illustrated in Figure 2 the right hand portion is similar to the burner of Figure 1 except that a third annular side wall portion 15 is disposed between the upper and lower parts 6 and 7 with the slots 14 of the ports 8 and the slots 13 and 14 of the ports 9 being constituted in the wall portion 15. Also the tube 10 is received in a counterbore recess 16 in the end wall of the lower part 7 which continues the tube to the inlet 11 of venturi outline. In the burners described above the upper and lower parts 6 and 7 are both formed from castings. In the burner illustrated in the left hand portion of Figure 2 the upper part 6 which also contains the flame ports 8 is of fabricated metal construction and the lower part 7 comprises a casing of cup-shaped outline through the closed end wall of which projects the intake tube 10 which is of tubular metal construction. The lower end of the tube is of frusto conical outline at 17 to define the venturi type inlet. In a modification the lower part may also be of pressed metal or other fabricated metal construction with a slotted annular port ring disposed between the side walls or skirts of the upper and lower parts. In a further modification flame retention means to stabilise the flames at the main flame ports may be provided by suitably altering the size and shape of the burner's outer flange or rim adjacent to the flame ports. The burners may also be constructed from ceramic material or glass. Due to the electricity insulative nature of the material this is of particular advantage when it is desired to incorporate an electrical igniter in the burner since no other insulator has to be provided. Our invention can be applied to other burners, for example to burners for gas cooker ovens, space heating appliances and gas-fired water heaters, and it is envisaged that all the burners will be suitable for use with natural and town gas, and liquid petroleum gases. Of course, such further burners will be of linear outline and may employ more than one intake tube projecting into the burner chamber. WHAT WE CLAIM IS:

1. A gas burner of the kind set forth for domestic appliances in which the intake tube is housed substantially within the body, and a flow path is defined in the body by way of which the gas/air mixture leaving the inner end of the tube is directed back towards the outer end of the tube and then towards the inner end again before issuing from jets or flame ports of the burner.

2. A gas burner according to Claim 1, in which the tube is housed wholly within the body of the burner.

3. A gas burner according to Claim 1 or 2, in which a burner chamber is defined within the body between opposed first and second end walls and a continuous side wall, and the tube projects through the first end wall to a position spaced by a relatively short distance from the second end wall, a passage forming part of the flow path whereby the gas/air mixture is directed away from the inner end of the tube and towards the outer end of the tube being defined by a space between the tube and the second end wall and between the tube and the side wall.

4. A gas burner according to Claim 3, in which the jets or flame ports are positioned in the side wall and each port comprises a first substantially axial portion extending from the passage towards the second end wall and directing the mixture towards the inner end of the tube, and a second substantially radial portion extending out of the body at the upper end of the first portion.

5. A gas burner according to Claim 4, in which the ports comprise an upper series of flame ports and a lower series of flame retention ports.

6. A gas burner according to any preceding claim in which the free outermost end of the intake tube has a venturi-type entry.

7. A gas burner according to any preceding claim in which the body is provided with location means for locating the burner with respect to the injector, which has a pipe connection to a supply of gas.

8. A gas burner according to Claim 7 as dependent from any of Claims 3 to 5, in which the tube is received in a counterbore recess in the first end wall, the recess continuing the tube to an inlet of venturi outline.

9. A gas burner substantially as herein described with reference to and as illustrated in Figure 1 of the accompanying drawings.

10. A gas burner substantially as herein described with reference to and as illustrated on the right hand portion of Figure 2 of the accompanying drawings.

11. A gas burner substantially as herein described with reference to and as illustrated on the left hand portion of Figure 2 of the accompanying drawings.